St. Paul, MN -- Minnesota Attorney General Lori Swanson today (Monday, July 19) filed a lawsuit against the federal government and a Chicago-area water control district to protect Lake Superior and the Great Lakes from the entry of Asian carp through infested Illinois waters.

The lawsuit was filed jointly by the Attorneys General of Minnesota, Michigan, Ohio, Wisconsin and Pennsylvania, who all represent Great Lakes states.

“The Great Lakes are an American treasure. By artificially connecting Illinois waters to the Great Lakes to carry sewage waste away from Chicago, the city put the Great Lakes at risk. This lawsuit asks for a court order to restore the natural barrier between Asian carp-infested Illinois waters and Lake Michigan to stop the entry of Asian carp into the Great Lakes,” said Attorney General Swanson.

The lawsuit was filed in United States District Court for the Northern District of Illinois against the U.S. Army Corps of Engineers, which operates the Chicago-area lock and dam system, and the Metropolitan Water Reclamation District of Greater Chicago, an Illinois local government agency that oversees Chicago-area waterways.

The lawsuit seeks a court order requiring the defendants to implement permanent measures to physically separate Asian carp-infested Illinois waters from Lake Michigan.

The threatened entry of Asian carp into the Great Lakes through Lake Michigan is a matter of pressing concern. In June, 2010, a bighead Asian carp was recovered six miles from Lake Michigan, past the electric barriers designated to keep Asian carp out of the Great Lakes. DNA testing late last year of Chicago-area waters indicated that Asian carp are present in the area.

Lake Superior is the largest fresh-water lake in the world. Attorney General Swanson noted that Minnesota has 140 miles of Lake Superior shoreline and that recreational and commercial fishing on Lake Superior, and tourism on the North Shore, are important to Minnesota’s economy.

“Minnesota is ‘The Land of 10,000 Lakes,’ and the biggest of all is Lake Superior. This lawsuit is about restoring proper stewardship for our Great Lakes,” said Attorney General Swanson.

The Illinois Department of Natural Resources recently stated that: “Once in Lake Michigan, this invasive species [Asian carp] could access many new tributaries connected to the Great Lakes. These fish aggressively compete with native commercial and sport fish for food. They are well suited to the water temperature, food supply, and lack of predators of the Great Lakes and could quickly become the dominant species. Once in the lake, it would be very difficult to control them.”

Asian carp are extremely destructive. They can weigh over 100 pounds, consume large amounts of food, and reproduce rapidly. They pose a threat to native fish species by reducing populations of native plants, an important staple for native fish.

Some Asian carp jump up to 10 feet out of the water when disturbed by the sound of watercraft, posing a public safety risk to boaters and water skiers, and causing damage to watercraft. Asian carp were brought to the United States by Southern catfish farmers to remove algae from fish ponds. They escaped those ponds during flooding in the 1990s and have since spread aggressively through the country’s waterways.

Illinois waters were not naturally connected to the Great Lakes. More than 100 years ago, however, Illinois built an artificial canal system to carry sewage waste away from Chicago. As a result, Illinois waters are now connected to the Great Lakes system. This man-made connection is what allows Asian carp-infested water to flow into the Great Lakes.